[Chameleon-dev] chameleon versioning and widget renaming

[Paul Spencer]

All,

bugs 632 and 377 concern renaming widgets that have been in existance 
for quite a while.  While the renaming itself is reasonably trivial, 
this will cause existing templates to break immediately.

To counteract this, I've added a widget renaming scheme in 
WidgetManager.php.

I don't want to support old widget names indefinitely, so the widget 
renaming is keyed to Chameleon versions.  There's no concept of a 
version in the code, so I have added the following in chameleon.php:

/*
  * chameleon API version.
  * The API version started with version 1.99.
  * It is used by some components (starting with the widget name
  * mapping in WidgetManger.php) to define an API version.  It
  * can be expected that the API will be consistent between POINT
  * versions but can change between MAJOR and MINOR versions.
  *
  * It could also be used for widgets that require a certain API
  * version to work in the future.
  *
  * There are 5 values defined:
  *
  * CHAMELEON_MAJOR_VERSION - the major release number
  * CHAMELEON_MINOR_VERSION - the minor release number, odd is dev, even 
is stable
  * CHAMELEON_POINT_VERSION - a bugfix release within a minor version
  * CHAMELEON_STATE_VERSION - a qualifier like ALPHA or BETA
  * CHAMELEON_VERSION - a combination of the above, in the form:
  *
  * 1.99.0
  * 2.2.0-beta3
  *
  *
  */
define( "CHAMELEON_MAJOR_VERSION", "1" );
define( "CHAMELEON_MINOR_VERSION", "99" );
define( "CHAMELEON_POINT_VERSION", "0" );
define( "CHAMELEON_STATE_VERSION", "beta3" );

define( "CHAMELEON_VERSION", CHAMELEON_MAJOR_VERSION.".".
                              CHAMELEON_MINOR_VERSION.
                              (CHAMELEON_POINT_VERSION == '' ? '' : "-" ).
                              CHAMELEON_STATE_VERSION );

Currently this is used only by the WidgetManager to associate versions 
with deprecated widget names.  But I can see us using this in the future 
when we distribute widget packs or individual widgets that might be 
installed into older (or newer) chameleon installations.  The comments 
in the code say it all ...

/*
  * global mapping array for widgets that change their name
  *
  * widgets that get their name changed can be registered here to ensure
  * backwards compatibility for several versions
  *
  * array uses old name as a key with new name and three version numbers:
  * version 1 - the version that the name changed
  * version 2 - the version at which warnings should appear
  * version 3 - the version at which errors should appear
  *
  * at version 2, widgets will still work under the old name but a 
warning will
  * be logged in the error manager
  *
  * at version 3, widgets will cease to work and will appear in RED in 
the template.
  *
  * example:
  * $GLOBALS['gaszRenamedWidgets']['MapDHTMLWidget'] =
  *     array( "MapDHTML", "1.99", "2.2", "2.4" );
  *
  * NOTE that only the MAJOR and MINOR numbers are used in this comparison
  */

$GLOBALS['gaszRenamedWidgets'] = array();

//bug MT 632: rename MapDHTML widget
$GLOBALS['gaszRenamedWidgets']['MapDHTMLWidget'] =
     array( "MapDHTML", "1.99", "2.2", "2.4" );

so that existing templates will work without warning until we declare 
version 2.2 in the defines, and won't work when we declare 2.4 in the 
defines.

Make sense?  This has all been committed to cvs (just now) so any 
problems should be reported asap.

Cheers,

Paul